programtokenizer.java

nesC写的heed算法

// $Id: ProgramTokenizer.java,v 1.1.14.3 2003/08/26 09:08:12 cssharp Exp $

/*									tab:4
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 * Copyright (c) 2002-2003 Intel Corporation
 * All rights reserved.
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/* Authors:	Phil Levis <[e-mail]>
 * Date:        Aug 8 2002
 * Desc:        Assembly program tokenizer for TinyOS VMs.
 *
 */

/**
 * @author Phil Levis <[e-mail]>
 */


package net.tinyos.vm_asm;

import java.io.*;

/**
 * This class reads in an ASCII assembly program and tokenizes it into
 * individual instructions. If an instruction has an embedded operand,
 * that operand can be fetched with <tt>argument()</tt>.
 *
 */

public class ProgramTokenizer {
    private StreamTokenizer tokenizer;
    private byte argument = 0;
    
    public ProgramTokenizer(Reader reader) throws IOException {
	tokenizer = new StreamTokenizer(reader);
	tokenizer.resetSyntax();
	tokenizer.eolIsSignificant(false);
	tokenizer.wordChars('A', 'Z');
	tokenizer.wordChars('a', 'z');
	tokenizer.whitespaceChars(0, 32); //Unreadable chars and whitespace
	tokenizer.whitespaceChars(127, 127); //DEL
	tokenizer.parseNumbers();
    }

    public boolean hasMoreInstructions() throws IOException{
	int type = tokenizer.nextToken();
	if (type == StreamTokenizer.TT_EOF) {
	    return false;
	}
	else {
	    tokenizer.pushBack();
	    return true;
	}
    }

    public byte argument() {
	return argument;
    }
    
    public String nextInstruction() throws IOException {
	int type = tokenizer.nextToken();
	if (type != StreamTokenizer.TT_WORD) {
	    throw new IOException("File parse failed on line " + tokenizer.lineno());
	}

	String instr = tokenizer.sval;
	//System.out.println("Parsing <" + instr + ">");
	
	type = tokenizer.nextToken();

	if (type == StreamTokenizer.TT_NUMBER) {
	    argument = (byte)tokenizer.nval;
	}
	else {
	    tokenizer.pushBack();
	}

	return instr;
    }
}